Structural Diversity among Edwardsiellaceae Core Oligosaccharides

The Edwardsiella genus presents five different pathogenic species: Edwardsiella tarda, E. anguillarum, E. piscicida, E. hoshinae and E. ictaluri. These species cause infections mainly in fish, but they can also infect reptiles, birds or humans. Lipopolysaccharide (endotoxin) plays an important role in the pathogenesis of these bacteria. For the first time, the chemical structure and genomics of the lipopolysaccharide (LPS) core oligosaccharides of E. piscicida, E. anguillarum, E. hoshinae and E. ictaluri were studied. The complete gene assignments for all core biosynthesis gene functions were acquired. The structure of core oligosaccharides was investigated by H-1 and C-13 nuclear magnetic resonance (NMR) spectroscopy. The structures of E. piscicida and E. anguillarum core oligosaccharides show the presence of -> 3,4)-L-glycero-alpha-D-manno-Hepp, two terminal beta-D-Glcp, -> 2,3,7)-L-glycero-alpha-D-manno-Hepp, -> 7)-L-glycero-alpha-D-manno-Hepp, terminal alpha-D-GlcpN, two -> 4)-alpha-D-GalpA, -> 3)-alpha-D-GlcpNAc, terminal beta-D-Galp and -> 5-substituted Kdo. E. hoshinare core oligosaccharide shows only one terminal beta-D-Glcp, and instead of terminal beta-D-Galp a terminal alpha-D-GlcpNAc. E. ictaluri core oligosaccharide shows only one terminal beta-D-Glcp, one -> 4)-alpha-D-GalpA and do not have terminal alpha-D-GlcpN (see complementary figure).

Automated summary

The Edwardsiella genus consists of five species that can cause infections in fish, reptiles, birds, and humans. The lipopolysaccharide (LPS) core oligosaccharides of E. piscicida, E. anguillarum, E. hoshinae, and E. ictaluri were studied for the first time, including their chemical structure and genomics. The structures of the core oligosaccharides were determined using H-1 and C-13 nuclear magnetic resonance spectroscopy.